Thanks for the welcome and for your feedback!
Sorry if that was a little unclear, but that room is very much a terrible placeholder and absolutely not intended for any kind of feedback. The character sprite is what I'm looking for advice on.
(I'm planning to have the light source be from the right and front, so objects will be casting shadows to the rear left, which will give a much better frame of reference. I may also cheat the view à la Link to the Past in order to show some of the side of the platforms.) Please disregard the appearance of the world for now, I was simply trying to put the character in some form of context.
I've updated the sprite a bunch since this was posted. I need to tweak the shoulders on all of them, and the jawline on the middle one, but any further advice on the character would be greatly appreciated.

This looks pretty nice visually, and you make good use of lighting and texture, but I think your perspective could use a little work.
You could definitely make some nice 2d assets for a game with this style.

Out of curiosity, have you been playing Octopath Traveler? That game makes pretty good use of exactly this idea.
My thoughts after a quick overview:
I get a feeling that Alvis is involved with school in some way. A professor? He reminds me a little too much of Octopath's Cyrus.
Victoria seems a little haughty.
Krissy is a pacifist. “That’s enough for now.” sticks out from the others to me, as it seems much less gentle.
Rorsh doesn't convey much personality except being a warrior? “The battle may be over but conflict isn’t.” sounds kind of weird. Do you mean "The conflict"? I think you should change this line.
Erwin is a slacker who doesn't care.
Mariel is a 'genki girl'.
Sarah is always serious.
Fausty is... extremely weird? Their first three line suggest someone imbued with themselves and confident and speaks florally, while their fourth and fifth suggest someone who has a very... casual attitude towards language. I feel like there's a conflict.
Some of the solo lines feel very generic and stilted. Of note:
“Phew, the battle’s over.”
“I managed to stay alive.”
“This was enough to pass with my life.”
“Thank goodness the fight’s done.” (This one is especially bland and unsatisfying. 'I am glad we are no longer fighting'.)
Meanwhile, I particularly like a few of these:
“I wish I could forget this ever happened.”
“If I must, I’ll fight anything in my way.”
“Out of sight and out of mind.”
“Wake me up when something interesting happens.”
“Operation Relax is a go-go!”
“Let’s celebrate victory AFTER we return to base.”
“You’ve wasted enough of our time.”
“Cue fanfare!”
“As if I could lose to the likes of you.”
You have a few grammar errors here and there; I would recommend running these through a corrector, and, ideally, by an editor.
There's a few too many group quotes for me to go through all of them right now, but “I wish I knew even half as much knowledge that you know.” sounds extremely awkward because of the repeated 'knew'/'know'. "I wish I knew even half as much as you do."

I agree with Tom Sloper. Assuming there are some hints dropped that things are not as they seem, the twist that the player character was misleading the player all along would be an interesting one.
One possible way you could 'hint' at this would be to have some internal narration. When showing the player character's thoughts on other characters involved, the character paints them out as unreliable, which contradicts what the player can see from themselves of the NPCs doing good.
This is definitely something that could go great or bad, so I advice you to make sure you have a few trusted beta-players/readers who can give their thoughts.

I'm taking my first real shot at game development, and seeing as I'm doing it as a self-enrichment and creative hobby, more so than seeking to get a concrete project out in any reasonable amount of time, I'm taking this opportunity to dip my toe into the visual arts for the first time... essentially ever.
I've never really had an eye for art, and I'm looking to learn. With some guidance from tutorials and friends, I've made a basic character sprite, and would like some feedback and constructive criticism before I try and animate the character.
For the sake of context, I've gone ahead and stuck the character in a test room of the game which, it bears mentioning, has graphics in an extremely placeholder state.
Any feedback you can provide, be it for proportions, shading, general pixel art issues, or anything else, is extremely appreciated!

I like the visual design of the second option better, but I prefer the camera angle of the first.
I would suggest having the text on some form of opaque GUI box, as opposed to just overlaid, as it can prove rather difficult to read.